This project provides PDP-11 computer support at various levels for four Becton-Dickinson FACS II and one Coulter MDADS flow cytometry/electronic cell sorting instrument. Data acquisition is via an NIH-designed interface to the computer. Data display and analysis for high sample throughput is the principal system feature. Software currently running under the RT-11 operating system is being converted to function under the RSX-11M operating system in order to allow more sophisticated recordkeeping and more effective support of current and anticipated workloads.